Potato Salad with Wasabi Mayonnaise

The incendiary Japanese horseradish called wasabi is traditionally served as a condiment to fish, particularly in sashimi or sushi style. I’ve used it here to enliven a potato salad that would go well with any picnic or cold buffet. I’ve given the wasabi mayonnaise as a separate recipe, immediately following this one, since it has a personality all its own.